Safety switch device



Nov. 17, 1931. LEINAU 1,832,712

SAFETY SWITCH DEVICE Filed Oct. 2, 1929 gwoozwtoz eatin Patented Nov. 17, 1931' UNITED "STATES PATENT "OFFICE NORMAN LEINAU, 0E YoNKEns, NEW YORK, ASSIGNOR, BY MESNE ASSIGNMENTS, T0; NORLEIN RESEARCH LABORATORIES, or 'HACKENSACK, NEW, JERSEY, A conrom TION OF NEW JERSEY.

' SAFETY SWITCH DEVICE 'Application filedpctobei' 2, 1929.. Serial o. 396,862.

My invention consists in new and useful im rovements in a safety appliance for indidanger in connection with boilers and the lilieand includes means for automatically breaking anelectric circuit to eithershut ofl the current of the heater or actuate other suitable means of control. l

The object of my invention is to provide a device of this character which will'not only warn the operator or occupant of the prerm ises, of any impending danger due to low water in a boiler, but will automatically termif nate the operation of the heating mechanism until said operator actually removes the danger by replenishing the water supply and resetsthe safety device hand.

Heretofore' with devices ofthisf'general type, athermostat, diaphragm or other similar element has been employed to automatically break a circuitto shut off the source of "heat, but when the water in the boiler fell below the temperature required to operate the device, said device automatically returned to a contacting position which in turn caused theheating mechanism to again be set into operation, which in 'time,-'if not attended to, would burn out the boiler and result in considerable damage. It is to overcome the disadvantages and dangers of this type of de- 7 vicethat I have evolved the present invention.

A further object ofjmy invention is to provide a. safety device, the working parts of which are outside of the boiler, thereby not only being safer but more readily accessible.

A still further object of my invention is to provide an adjustable structure which may be set for various temperatures,the working parts of said device belng inclosed w1th1n a housing equipped with a transparent cover,

whereby the works are visible from the outside.

With the above and other objects in view 1 which will appear as the description proceeds, myinvention consists in the novel features herein set forth, illustrated in theac- 1 companying drawings and more particularly pointed out in the appended claims.

Referring to the drawings in which 1111+ merals of like character designate similar provided at its outer end or mouth with an internally threaded c0llar3. v 1 4 represents an elongated tube," closed at one end by a cap 4; and threaded at its other end to engage an enlarged cylindricalmemher 5 This member 5 is externally threaded at the end which engagesthe tube4 whereby it is adapted to be screwed into the collar 3 to secure said tube within the chamber 2 of the boiler}. The member 5 is squared as at 6 to facilitate the application of a wrench or other suitable tool in securing the device in place. j y

7 designates a'base member'a'dapted to-be secured to the outer end of the member 5 at its lower end by means of an L-couplingo its upper extremity carrying the lower end of a Bourdon tube 8, said Bourdon tube being in communication with the tube 4 by means of a conduit extending through I the base member 7 and the member 5.- Any suitableliquid may be employed within the tube 4 and Bourdon tube 8 but I prefer the use of alcohol. 1

Surrounding the Bourdon tube and supported by the base member 7 is a housing 9 for inclosing the working parts of the device.

- An insulating. base 10 issecured to the rear Wall of the housing 9,'substantially centrally thereof and within the confines of the Bourdon tube, said base 10 carrying an adjustable pivoted resilient contact arm 11, thefree end of which is provided withv a lug 12 of insulating material. F

13 represents a stationary contact arm also I carried by said base10 and adapted to engage Fig; 3 is a. side elevation from the side ,op- I the switch is opened.

the resilient contact arm 11 when the latter is forced outwardly, thus completing a circuit for operating the boiler heating mechanism (not shown). The arm 11 is retained in contact position with the arm 13 by means of the lug 12 on the end of the former which engages the end of the Bourdon tube, serving as a latch.

Intermediate the ends of the contact arm 11 I provide a series of apertures 14 whereby said arm when adjusted on its pivot is adapted to be secured in the proper position by means of a screw which extends through the desired aperture into the insulating base 10. If desired the outer face of the arm 11 may be provided with a graduated scale adjacent the series of apertures.

15 represents a cover adapted to fit over the open end or mouth of the housing 9 and provided with a transparent window 16, whereby the working parts of the device are visible from the outside. 7

17 represents a resetting device which extends inwardly through the rim of the cover 15 and is secured to the insulating lug 1:2 on the end of the contact arm 11, whereby the latter may be pulled outwardly and reset.

On the end of the lug 12 and projecting longitudinally outwardly therefrom I provide an indicating arm 18 which extends through a transverse slot 19 in the annular wall of the housing 9, the outer surface of which wall is provided with suitable indicia to enable the operator to ascertain the position of the resilient contact 11.

Having thus described the construction of my improved device, its operation is as follows:

When the boiler heating mechanism is in operation the elements of the safety device are in the positions shown in Fig. 4 with the arms 11 and 13 in contact, closing the circuit, said arm 11 being retained in its contacting position by the end of the Bourdon tube engaging the lug 12.

If the water in the boiler becomes lo\ and its temperature reaches the danger point, predetermined by setting the contact arm 11, the alcohol or other fluid in the tube elexpands and causes the end of the Bourdon tube to be moved outwardly releasing the lug 12 and permitting the resilient arm 11 to spring inwardly breaking its contact with the arm 13. This of course, opens the electric circuit and automatically shuts off the heating mechamsm.

- Information that the heathas been turned 011' may be transmitted to the occupant of the premises or operator of the apparatus in any suitable manner such as a bell operated when But the important feature is that before the heating mechanism is turned on again it is necessary for the operator to reset the devieeby hand, before which,

of course, he corrects the water level in the boiler and removes any danger.

When it is desired to again set the heating mechanism into operation, the resetting device 17 is pulled outwardly by hand and with it the resilient arm 11 permitting the Bourdon tube to spring inwardly and again lock the contact arms in circuit making positions.

From the foregoing it is believed that the advantages of my invention may be readily understood by those skilled in the art, it being borne in mind that numerous changes may be made in the details of the construcion without departing from the spirit of the invention.

It will also be noted that this device may be employed with various types of apparatus such as, oil heaters, fire alarms, hot water heaters, etc.

It will be further noted that while I have shown and described the resetting device 17 applied to the front of the structure and operated by pulling out, I may, with equal advantage, insert the same from the rear wall of the housing 9, passing it through the insulating block 10 where it will abut the rear face of the resilient arm 11, whereby the latter may be pushed into contact position rather than pulled. A suitable spring may be employed on the resetting device to return the same to its normal position.

lVhat I claim and desire to secure by Letters Patent is 1. In a safety switch device for electrically controlled ap aratus, an expansible member and a mova le contact lying in the same lane but operatively movable in difierent p anes, said expansible member being arranged to enga e said contact to lock the same in circuit c osing position, when retracted, and to disengage said contact when extended.

2. In a safety switch device for electrically controlled apparatus, a Bourdon tube and a movable contact, lying in the same plane but movable in planes at substantially right angles to one another, the end of said Bourdon tube being arranged to engage said contact to lock the same in circuit closing position when retracted, and to disengage said. contact when extended.

3. In a safety switch device for electrically controlled apparatus, a stationary contact, a movable contact normally lying in substantially the same plane and adapted to engage said stationary contact to close an electrical circuit, and a heat actuated expansible member adapted to engage said movable contact when retracted, to maintain said contacts in circuit closing position, said member disengaging said movable contact when extended, the plane of movement of sald second contact belng at substantially right angles to that of said expans'ible member.

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4:. In a safety switch device for electri- 10. A device as claimed in claim 7, wherecally controlled apparatus, a stationary conin the movement of said movable contact is tact,amovable contact adapted to engage said in a plane at substantially right angles to stationary contact to complete an electric that of said expanslble member.

circuit, the end of said movable contact being provided with an insulating member,

an expansible member, the free end of which is adapted to engage the insulating member on said movable contact when retracted, to maintain said contacts 1n engage1nent,sa1d

expansible, member disengaging said insulating member when extended, the movement of said second contact being in a lane at substantially right angles to that 0 said expansible member.

5. In a safety switch cally controlled apparatus, a stationary contact, a movable contact adapted to engage said stationary contact to complete an electric circuit, the end of said movable contact being provided with an insulating member, a Bourdon tube, the free end of which is adapted to engage the insulating member on'said movable contact when retracted, to maintain said contacts in engagement, said tube disengaging said insulating member when extended, the movement of said second contact being in aplane at substantially right angles to that of said Bourdon tube and manually controlled means mounted on said movable contact for resetting the same.

6. A safety switch device comprising a housing, a Bourdon tube and a resilient contact in said housing, the latter being secured at one end and provided with an insulating member at its free end, the free end of said Bourdon tube being arranged to engage the free end of said contact, when retracted, to

lock the same in circuit closing position, and

to disengage said contact when extended, and a resetting device secured to the free end of said resilient contact, projecting through said housing.

'7. A safety switch device comprising a housing, an insulating block in said housing, a stationary contact secured to said block, a

movable contact also secured to said block,

a heat actuated expansible member rigidly secured at one end within said housing, its other end being free and adapted to engage said movable contact, when retracted, to lock the same in circuit closing position, and to disengage said contact when extended, said movable contact being adjustable in the plane of movement of said expansible member.

8. A device as claimed in claim 7 wherein the wall of said housing is provided with aslot, said movable contact having an indieating arm secured thereto and extending through said slot to indicate the position of said contact.

9. A device as claimed in claim 7 wherein said stationary contact and said movable contact are adjustable in the plane of movement of said expansible member.

device for electri- NORMAN LEINAU. 

